Human-derived metastin (also termed KiSS-1 peptide) (WO 00/24890) and mouse or rat-derived metastin (WO 01/75104 2) are known. Also, sustained released preparations containing metastin are known ((WO 02/85399).
Reportedly, metastin has an effect of suppressing cancer metastasis and is therefore effective for preventing/treating cancers (for example, lung cancer, gastric cancer, liver cancer, pancreatic cancer, colorectal cancer, rectal cancer, colonic cancer, prostate cancer, ovarian cancer, cervical cancer, breast cancer, renal cancer, bladder cancer, brain tumor, etc.); metastin also has an effect of regulating a function of the pancreas and is effective for preventing/treating pancreatic diseases (e.g., acute or chronic pancreatitis, pancreatic cancer, etc.); and metastin further has an effect of regulating a function of the placenta and is effective for preventing/treating choriocarcinoma, hydatid moles, invasive moles, miscarriage, fetal hypoplasia, sugar dysbolism, lipid dysbolism or abnormal delivery (WO00/24890; WO01/75104 2; WO 02/85399).